UK Construction Safety Glossary

Definitions of key UK construction health and safety terms including RAMS, CDM 2015, COSHH, CPP, PPE, risk assessments, method statements, and more. This glossary is designed for construction professionals, site managers, and health and safety officers working under UK regulations.

Asbestos: A group of naturally occurring fibrous minerals that were widely used in UK construction until their ban in 1999. Disturbing asbestos-containing materials releases fibres that, when inhaled, can cause serious diseases including mesothelioma, asbestosis, and lung cancer. The Control of Asbestos Regulations 2012 require a duty to manage asbestos in non-domestic premises and mandate surveys before refurbishment or demolition. Licensed asbestos removal contractors must be used for most types of work with high-risk asbestos materials.
CDM 2015 (Construction (Design and Management) Regulations 2015): The primary set of regulations governing health and safety on construction projects in Great Britain. CDM 2015 places duties on clients, principal designers, principal contractors, designers, and contractors to plan, manage, and coordinate work so that risks are controlled throughout the project lifecycle. Compliance is a legal requirement for virtually all construction work.
CHAS (Contractors Health and Safety Assessment Scheme): A UK pre-qualification health and safety assessment scheme that verifies a contractor's ability to comply with current UK health and safety legislation. CHAS accreditation is recognised by many principal contractors and public sector clients as evidence that a contractor has demonstrated adequate health and safety management arrangements. CHAS is a member of SSIP, and its assessments are mutually recognised by other SSIP member schemes.
Client (CDM): Under CDM 2015, the client is any person or organisation for whom a construction project is carried out. The client has a duty to make suitable arrangements for managing the project, including ensuring adequate time and resources are allocated and that relevant information is provided to designers and contractors. On domestic projects the client's duties normally transfer to the contractor or principal contractor.
Competent Person: An individual who has sufficient training, experience, knowledge, and other qualities to carry out a specific task safely. Competence requirements vary depending on the complexity of the work and the nature of the hazards, but the duty holder must always be able to demonstrate that the person appointed is capable of fulfilling the role without risk to themselves or others. Competence is not a single qualification but a combination of skills, knowledge, and practical experience.
Confined Space: Any enclosed or partially enclosed space that is not designed for continuous human occupancy and where there is a reasonably foreseeable risk of serious injury from hazardous substances, lack of oxygen, or free-flowing solids. Construction examples include excavations, manholes, culverts, tanks, and voids. The Confined Spaces Regulations 1997 require a specific risk assessment, and in most cases entry should only take place with a permit to work. Non-entry solutions should always be considered first.
Constructionline: A UK prequalification and supply chain management scheme used by principal contractors, public-sector clients, and large buyers to verify contractor health and safety, financial, and business standards. Constructionline has multiple membership tiers (Standard, Silver, Gold, and Platinum), with higher tiers requiring progressively more rigorous evidence. Health and safety documentation — including RAMS, COSHH assessments, training records, and insurance — is a core evidence area at all membership levels. RAMS AI is independent and is not endorsed by Constructionline.
Contractor: Any person or organisation that carries out, manages, or controls construction work. Under CDM 2015, contractors have a duty to plan, manage, and monitor construction work to ensure it is carried out without risks so far as reasonably practicable. Contractors must also provide suitable information, instruction, training, and supervision to workers, and cooperate with the principal contractor on projects involving more than one contractor.
Control Measures: The steps taken to eliminate or reduce the likelihood or severity of harm from an identified hazard. In UK health and safety practice, control measures are typically considered in a hierarchy: eliminate the hazard, then substitute, then engineering controls, then administrative controls, and finally PPE/RPE. A RAMS document specifies the control measures that will be applied to each identified hazard.
COSHH (Control of Substances Hazardous to Health): A set of regulations requiring employers to assess and control exposure to hazardous substances in the workplace. A COSHH assessment identifies the substances used, evaluates the risks they pose, and sets out the control measures needed to protect workers. Common construction substances covered include cement dust, silica, solvents, wood dust, and isocyanates.
COSHH Assessment: A documented evaluation required under the Control of Substances Hazardous to Health Regulations 2002 (COSHH) that identifies substances hazardous to health used in a task, assesses the exposure routes and health effects, and specifies the control measures needed to protect workers. A COSHH assessment should be completed before work starts and referenced in or appended to the relevant RAMS document. It must be reviewed when work conditions change.
CPP (Construction Phase Plan): A document required under CDM 2015 that sets out the health and safety arrangements, site rules, and specific measures needed to manage risk during the construction phase. The principal contractor must prepare the CPP before work begins on site and keep it updated throughout the project. It acts as a project-level framework within which individual contractors produce their RAMS.
Document Version Control: A system for managing revisions to a RAMS or other safety document so that the current version can be identified and previous versions are retained for reference. Each revision should be assigned a new version number and date. Workers must be re-briefed whenever the document is updated. Principal contractors expect RAMS to be versioned so they can confirm the document they approved is the one being used on site. Absence of version control is a common reason for RAMS to be queried.
Duty Holder: Any person or organisation that has a legal responsibility under health and safety legislation. Under CDM 2015 the duty holders are the client, principal designer, principal contractor, designers, and contractors. Each duty holder has specific obligations that must be fulfilled to ensure the safety of workers and others affected by the construction work.
Dynamic Risk Assessment: A real-time assessment of risks that occurs during a work activity when conditions change unexpectedly — for example, when previously unknown hazards are encountered, when weather conditions deteriorate, or when the site layout changes. Dynamic risk assessment is a supplement to, not a replacement for, documented RAMS. Workers should be trained to recognise when conditions have changed beyond the scope of the written RAMS and to stop work and seek guidance or reassessment where necessary.
Emergency Arrangements: The plans and procedures in place to manage foreseeable emergencies on a construction site, including fire, medical emergencies, structural collapse, chemical spills, and services strikes. CDM 2015 requires emergency arrangements to be set out in the Construction Phase Plan. They must include evacuation procedures, assembly points, emergency contacts, first aid provision, and communication arrangements. All workers must be made aware of emergency arrangements as part of their site induction.
Environmental Controls: Measures taken to prevent or minimise the impact of construction activities on the natural environment, including air, water, soil, and ecological habitats. Environmental controls on construction sites include dust suppression, waste segregation and disposal, containment of surface water runoff, prevention of chemical spills, control of noise and vibration, and protection of trees and watercourses. Environmental controls may be required under planning conditions and environmental legislation, and are often included in the Construction Phase Plan.
F10 (F10 Notification): The official form used to notify the Health and Safety Executive of a notifiable construction project under CDM 2015. The F10 must include details of the client, principal designer, principal contractor, project address, planned start date, and estimated duration. It must be submitted before the construction phase begins and displayed prominently on site.
Fire Safety on Construction Sites: The measures required to prevent fire and protect workers on construction sites. Key elements include hot works permits, fire points with appropriate extinguishers, clearly marked escape routes, temporary fire detection, controlled storage of combustible materials, and site-specific fire risk assessments. The Joint Code of Practice (JCoP) on fire protection during construction and building renovation provides the industry standard for managing fire risk on UK sites.
Generic RAMS: A RAMS document that uses standard, non-site-specific language and has not been adapted to reflect the actual work, site conditions, or hazards of the current project. Generic RAMS often contain hazard lists copied from previous jobs, vague control measures, and incorrect site details. They are a leading cause of RAMS rejection by principal contractors and do not satisfy the legal requirement for a suitable and sufficient risk assessment.
HAVS (Hand-Arm Vibration Syndrome): A condition caused by regular and prolonged exposure to hand-arm vibration from power tools and equipment such as breakers, grinders, and compactors. HAVS can cause permanent damage to nerves, blood vessels, muscles, and joints in the hands and arms. The Control of Vibration at Work Regulations 2005 set exposure action values (EAV) and exposure limit values (ELV) that employers must comply with. Workers at risk require health surveillance.
Hazard: Anything that has the potential to cause harm, including physical agents, chemical substances, biological organisms, and psychosocial factors. In construction, common hazards include working at height, moving machinery, electrical installations, manual handling, and hazardous substances. Identifying hazards is the first step in the risk assessment process.
Health and Safety File: A document compiled during a construction project that contains information needed to ensure health and safety during any subsequent work on the structure, such as maintenance, refurbishment, or demolition. The principal designer is responsible for preparing and updating the file, which is handed to the client on completion. It must include as-built drawings, details of materials used, and information about residual risks.
Hot Works: Any work involving an ignition source with the potential to start a fire, including welding, cutting (thermal), grinding, brazing, soldering, use of open-flame torches, and work with bitumen boilers. Hot works on construction sites require a permit to work system. The permit defines the area, duration, and precautions — including fire watches during and after work — to prevent fire from starting or spreading. Hot works are a leading cause of construction site fires in the UK.
HSE (Health and Safety Executive): The UK government agency responsible for the regulation and enforcement of workplace health, safety, and welfare legislation. The HSE inspects construction sites, investigates accidents, publishes guidance (such as Approved Codes of Practice and industry guidance notes), and has the power to issue improvement notices, prohibition notices, and prosecute offenders. The HSE maintains the EH40 Workplace Exposure Limits document and numerous sector-specific guidance publications.
Initial Risk: The level of risk present before any control measures are applied. In a RAMS risk matrix, the initial risk (also called the pre-control risk or inherent risk) is calculated by scoring the likelihood and severity of a hazard without taking into account the controls that will be put in place. The initial risk rating provides a baseline that demonstrates the need for controls. Once controls are applied, the residual risk rating confirms that risk has been reduced to an acceptable level.
LEV (Local Exhaust Ventilation): An engineering control system designed to capture airborne contaminants — dust, fume, vapour — at or near the source of generation before they enter the worker's breathing zone. LEV is a key control measure under COSHH and is commonly used for tasks such as cutting concrete, grinding metal, and sanding wood. On-tool extraction (e.g. vacuum attachment on angle grinders) is a common form of LEV in construction. LEV systems must be examined and tested at least every 14 months.
LOLER (Lifting Operations and Lifting Equipment Regulations 1998): Regulations that require every lifting operation to be properly planned by a competent person, appropriately supervised, and carried out safely. LOLER applies to all work equipment used for lifting or lowering loads, including cranes, hoists, forklift trucks, and lifting accessories such as slings and shackles. Equipment must be thoroughly examined at specified intervals and a written record kept.
Manual Handling: Any transporting or supporting of a load by bodily force, including lifting, putting down, pushing, pulling, carrying, or moving a load. Manual handling is one of the most common causes of injury in construction, particularly musculoskeletal disorders affecting the back, shoulders, and upper limbs. The Manual Handling Operations Regulations 1992 require employers to avoid hazardous manual handling where reasonably practicable, assess unavoidable operations, and reduce the risk of injury.
Method Statement: A written document that describes, step by step, how a work activity will be carried out safely. A method statement typically covers the sequence of operations, equipment to be used, personnel involved, and the control measures that will be applied to manage identified risks. It is often paired with a risk assessment to form part of a RAMS package.
Near Miss: An unplanned event that did not result in injury, illness, or damage but had the potential to do so. Reporting and investigating near misses is a key part of proactive safety management because it helps organisations identify weaknesses in their controls before a serious incident occurs. A strong near-miss reporting culture is widely regarded as a leading indicator of good safety performance.
Notifiable Project: Under CDM 2015, a construction project is notifiable to the HSE if it will last longer than 30 working days and have more than 20 workers working simultaneously at any point, or if it exceeds 500 person-days of construction work. The client must notify the HSE using an F10 form before the construction phase begins.
Permit to Work: A formal, documented system used to control high-risk work activities such as hot works, confined space entry, electrical isolation, and work at height. A permit to work records what work is to be done, the hazards involved, the precautions required, and confirms that all precautions are in place before work starts. It must be issued and authorised by a competent person, with a clear handback procedure when work is complete.
PPE (Personal Protective Equipment): Equipment worn or held by a worker to protect against one or more risks to health and safety. Common construction PPE includes hard hats, high-visibility clothing, safety boots, gloves, eye protection, and hearing protection. PPE should always be treated as the last line of defence, used only after other control measures have been considered and applied. Employers must provide PPE free of charge and ensure workers are trained in its correct use.
Prequalification: The process by which a contractor demonstrates their health and safety competence, financial stability, and technical capability to a client or principal contractor before being approved to tender or work on a project. In UK construction, prequalification is commonly conducted through SSIP-accredited schemes (such as CHAS, Constructionline, SafeContractor, or SMAS) or via bespoke client questionnaires. Health and safety documentation — including RAMS, risk assessments, COSHH assessments, training records, and insurances — forms a central part of most prequalification submissions.
Principal Contractor: The contractor appointed by the client under CDM 2015 to plan, manage, monitor, and coordinate health and safety during the construction phase when more than one contractor is involved. The principal contractor must ensure that a Construction Phase Plan is in place, that site rules are established, and that all workers receive appropriate induction and training. They are the primary point of contact for health and safety on site.
Principal Designer: The designer appointed by the client under CDM 2015 to plan, manage, monitor, and coordinate health and safety during the pre-construction phase when more than one contractor is involved. The principal designer must identify, eliminate, and control foreseeable risks that may arise during construction and throughout the life of the building. They are also responsible for preparing the health and safety file.
PUWER (Provision and Use of Work Equipment Regulations 1998): Regulations that require work equipment to be suitable for its intended use, maintained in a safe condition, inspected regularly, and used only by trained and competent persons. PUWER applies to all work equipment from hand tools to complex machinery. Employers must ensure guards and protective devices are in place and that equipment is used in accordance with manufacturer instructions.
RAMS (Risk Assessment and Method Statement): A combined document that brings together a risk assessment and a method statement for a specific work activity. The risk assessment identifies potential hazards, evaluates the likelihood and severity of harm, and sets out control measures. The method statement then describes the step-by-step safe procedure for carrying out the work. RAMS are a fundamental requirement on UK construction sites and are routinely required by principal contractors before subcontractors start their scope.
RAMS Briefing: The process of communicating the content of a RAMS document to the workers who will carry out the task, typically before work starts. A RAMS briefing confirms that workers understand the hazards involved, the control measures in place, and the safe sequence of work. Workers usually sign a record to confirm they attended the briefing. This is distinct from a site induction (which covers site-wide rules) and a toolbox talk (which covers a specific safety topic).
RAMS Rejection: The decision by a principal contractor or reviewing organisation to decline a RAMS document and request revision before allowing work to proceed. Common reasons for rejection include generic or reused content, incorrect site details, missing hazards, vague control measures, incomplete method statements, missing emergency arrangements, and absent competent-person sign-off. Rejected RAMS can delay a subcontractor's programme start date. Understanding the typical rejection reasons helps contractors produce better first-draft submissions.
RAMS Review: The process of checking a completed RAMS document before it is submitted to a principal contractor or used to brief a workforce. A RAMS review is typically carried out by a competent person — someone with relevant knowledge of the site, trade, and hazards involved. The review checks that the scope is accurate, hazards are relevant, controls are specific and achievable, the method statement sequence is logical, and emergency arrangements are correct. RAMS must also be reviewed and updated whenever conditions change on site.
Residual Risk: The level of risk that remains after all reasonably practicable control measures have been identified and applied. No control measure can completely eliminate risk in all circumstances, so a residual risk will usually remain. A RAMS document should clearly state the residual risk rating after controls to demonstrate that risk has been reduced to an acceptable level.
RIDDOR (Reporting of Injuries, Diseases and Dangerous Occurrences Regulations 2013): Regulations that require employers, the self-employed, and people in control of work premises to report certain serious workplace accidents, occupational diseases, and specified dangerous occurrences to the HSE. Reportable injuries include fatalities, specified injuries (such as fractures and amputations), and over-seven-day incapacitation injuries. Accurate RIDDOR reporting helps the HSE identify trends and target intervention.
Risk: The likelihood that a hazard will actually cause harm, combined with the severity of the consequences if it does. Risk assessment involves evaluating each hazard to determine how likely it is to result in injury or ill health and how serious the outcome could be. The level of risk guides the choice and priority of control measures needed to protect workers.
Risk Assessment: A structured, documented evaluation of the hazards associated with a task, work area, or process. A risk assessment identifies what could go wrong, who might be harmed, how likely that harm is, how severe it could be, and what control measures are needed to reduce the risk to an acceptable level. In construction, risk assessments form the first component of a RAMS document and must be site-specific and task-specific.
Risk Matrix: A tool used to evaluate and prioritise risks by plotting the likelihood of a hazard occurring against the severity of its potential consequences. The matrix typically produces a risk rating (such as low, medium, or high) that helps duty holders decide which risks need the most urgent attention. It is a standard feature of construction risk assessments in the UK.
RPE (Respiratory Protective Equipment): Equipment worn over the nose and mouth (or the whole face or head) to protect the wearer against airborne hazards such as dust, fumes, vapours, and biological agents. RPE includes disposable FFP-rated dust masks, half-face and full-face respirators, and powered air-purifying respirators (PAPRs). The correct type must be selected for the specific hazard, and workers must be face-fit tested for tight-fitting RPE. Like all PPE, RPE is a last line of defence — engineering controls such as on-tool extraction should be used first.
Safe System of Work: A formal procedure that results from a systematic examination of a task to identify all the hazards and define safe methods of working. A safe system of work ensures that hazards are eliminated or that the remaining risks are minimised. It is often documented through a combination of risk assessments, method statements, and permits to work.
SafeContractor: A UK SSIP (Safety Schemes in Procurement) health and safety prequalification scheme operated by Alcumus. Contractors accredited by SafeContractor have demonstrated that their health and safety management systems, documentation, and competence meet a defined standard assessed by auditors. SafeContractor accreditation is mutually recognised by other SSIP member schemes. Health and safety documentation — including risk assessments, method statements, and competence records — forms a core part of the assessment. RAMS AI is independent and is not endorsed by SafeContractor.
Sequence of Works: The step-by-step order in which a work activity is planned to be carried out, documented as part of the method statement within a RAMS. The sequence describes each operation in the correct order — including access and set-up, the work itself, testing or commissioning, and clearance. A logical, coherent sequence demonstrates that the work has been properly planned and is a key element that principal contractors check during RAMS review.
Silica Dust: Fine airborne particles of crystalline silica generated when silica-containing materials — including concrete, stone, brick, and sand — are cut, drilled, ground, or crushed. Inhalation of respirable crystalline silica (RCS) is a significant occupational health hazard in construction, causing silicosis (a progressive and irreversible lung disease), lung cancer, and other respiratory conditions. The WEL for RCS is 0.1 mg/m³ (8-hour TWA). Control measures include wet cutting, on-tool extraction, and appropriate RPE. Workers exposed to silica dust may require health surveillance.
Site Induction: A mandatory briefing given to every worker before they begin work on a construction site. The induction covers site-specific hazards, emergency procedures, welfare arrangements, site rules, and the location of key facilities. The principal contractor is responsible for ensuring that all workers, subcontractors, and visitors receive an appropriate induction before they enter the working areas of the site.
Site-Specific RAMS: A RAMS document prepared for a particular site, scope, and set of site conditions — not a generic or template document adapted from a previous job. Site-specific RAMS name the correct site address, client, and principal contractor, identify hazards relevant to the actual work and location, and include emergency arrangements specific to that site. Principal contractors routinely reject RAMS that are not sufficiently site-specific.
SSIP (Safety Schemes in Procurement): A forum of construction health and safety pre-qualification scheme operators that have agreed common minimum assessment standards. SSIP member schemes — which include CHAS, Constructionline, and others — assess contractors against a core criteria set covering health and safety management, competence, and arrangements. Achieving accreditation through one SSIP-member scheme should be mutually recognised by other member schemes, reducing the assessment burden on contractors.
Subcontractor: A contractor appointed by a principal contractor or main contractor to carry out a specific part of the construction work. Subcontractors are typically specialist trades — such as electrical, plumbing, or steelwork contractors — and are responsible for the health and safety of their own workers and for producing their own RAMS. They must cooperate with the principal contractor and comply with the site rules set out in the Construction Phase Plan.
Temporary Works: Any engineered structure used to support or protect a permanent works structure or the surrounding environment during construction. Examples include formwork, falsework, shoring, propping, and temporary access platforms. Temporary works must be designed by a competent engineer and managed through a formal temporary works procedure including design, checking, installation, and removal.
Toolbox Talk: A short, focused safety briefing delivered to workers on site, usually lasting between five and fifteen minutes. Toolbox talks cover a single topic relevant to the current work activities, such as manual handling, working at height, or the use of specific equipment. Attendance must be recorded and signed. They are an effective way to reinforce safe working practices and keep health and safety front of mind throughout a project.
WEL (Workplace Exposure Limit): The maximum concentration of an airborne substance to which workers may be exposed over a specified reference period without risk to health. WELs are set by the HSE and published in EH40 (Workplace Exposure Limits). They are expressed as a time-weighted average (TWA) over 8 hours, and in many cases a short-term exposure limit (STEL) over 15 minutes. Employers must not exceed a WEL and should reduce exposure further so far as is reasonably practicable.
Welfare Facilities: The amenities that must be provided on a construction site to protect the health and wellbeing of workers. Under CDM 2015, welfare facilities include toilets, washing stations with hot and cold running water, drinking water, changing areas, rest facilities, and somewhere to heat food. The principal contractor must ensure these facilities are available from the start of the construction phase and maintained throughout.
Work at Height Regulations 2005: Regulations that apply to all work at height where there is a risk of a fall liable to cause personal injury. They require duty holders to avoid work at height where possible, prevent falls using appropriate equipment, and mitigate the consequences of any fall. The regulations establish a hierarchy of controls and apply to all industries, but have particular significance for construction.
Working at Height: Any work carried out in a place where a person could fall a distance liable to cause personal injury. This includes work on ladders, scaffolds, roofs, and mobile elevated work platforms, as well as work near openings, edges, and fragile surfaces. The Work at Height Regulations 2005 require employers to follow a hierarchy of controls: avoid work at height where possible, prevent falls using appropriate equipment, and mitigate the consequences of any fall.

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